1) Field of the Invention
The invention relates to fiber optic devices. More particularly, the invention relates to a method of manufacturing fiber optic devices that uses functional components inserted in the optical path.
2) Description of the Prior Art
Several in-line optical fiber devices use the insertion of optical components between two optical fibers for performing various functions as spectral filtering, spatial filtering, beam splitting, sensing, isolating or polarizing. Most devices use lenses to collimate a light beam exiting an input optical fiber and to collect the light beam to an output optical fiber after propagation across the optical component or components. Precise alignment and high mechanical stability of the optical fiber cores and lenses are required to obtain a collimated beam.
The use of collimating lenses may not be necessary when using very thin optical component which reduces the optical path length between the two fibers. Alignment of the fiber cores requires high precision and high mechanical stability in order to optimize light collection at the output optical fiber and to minimize insertion loss and insertion loss variation. The high mechanical requirements are difficult to achieve in severe environmental conditions.
The prior art has not completely fulfilled requirements of insertion loss, alignment and mechanical stability for optical fiber devices using in-line insertion of optical components. There is thus a need for a method of manufacturing of optical fiber devices that overcomes at least some of the above-mentioned drawbacks.